Microhematocrit reader for centrifuges



Feb. 2, 1965 G. GODA ETAL MICROHEMATOCRIT READER FOR CENTRIFUGES Filed Dec. 4, 1961 FIG.3

INVENTORS. GEORGE GODA MARVIN A. ASNES 6%5Mm" FIG. I

A T TOONE Y.

United States Patent Cfiice 3,168,473 Patented Feb. 2, 1965 3,168,473 MICRGHEMATOCRIT READER FOR CENTRIFUGES George Goda and Marvin A. Asnes, New York, N.Y.,

assignors to Clay-Adams, Inc., New York, N.Y., a corporation of New York Filed Dec. 4, 1961, Ser. No. 156,871 12 Claims. (Cl. 23326) This invention relates to devices for making hematocrit determinations, and more particularly concerns hematocrit readers and hematocrit readers in association with centrifuges.

In making hematocrit determinations, it is conventional to first centrifuge the blood sample as contained in a capillary tube; remove the centrifuged tube from the centrifuge; and then associate such tube with a special reading device which gives the percentage reading for the packed red cells, in a known manner.

Such known procedures not only require repeated handling of the tubes, which may lead to errors due to mixup of sample tubes; and breakage of tubes; but also reduces the rate of determinations. Accordingly, one object of this invention is to provide an improved hematocrit reader which may form part of a centrifuge and is thus capable of use immediately after the centrifuging fiperation and while thetubes are still on the centrifuge ead.

Another object of this invention is to provide an improved hematocrit reader Which takes the form of a sample tube holder of transparent material and is asso ciated with a centrifuge head carrying on its surface percentage reading markings visible through the holder, whereby simple manipulation of the holder while still on the centrifuge will provide direct percentage readings.

A further object of this invention is to provide an improved reading device including a tray for carrying sample tubes in a radial disposition for centrifuging or other treatment, together with a transparent cover arranged for relative rotation in respect to the tray, the cover carrying percentage markings and adapted upon rotation to register the opposite ends of a sample in a tube with selected marking lines, to provide a direct percentage reading of a stratification line in the sample.

Still another object of this invention is to provide an improved capillary tube holder which may be carried to and from processing equipment and includes means for releasably retaining the tubes thereon against accidental dislodgment.

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

In the drawing,

FIG. 1 is a vertical sectional view of a centrifuge and reader embodying the invention;

FIG. 2 is a top plan view of a portion thereof, with the cover removed;

FIG. 3 is a top plan view of a portion of a cover showing another form of the invention;

FIG. 4 is a view similar to that of FIG. 2, showing another embodiment of the invention;

FIG. 5 is a sectional view taken on the line 55 of FIG. 4; and

FIG. 6 is a sectional view taken on the line 66 of FIG. 4.

In accordance with one embodiment of the invention, there is provided a centrifuge having a horizontally disposed, flat circular head rotatable about a vertical axis, being driven by a motor and of the type generally shown in Patent 2,783,938. However, such device is provided with a tray removably mounted on the head and arranged for relative rotation; the tray being formed of transparent material and adapted to carry capillary tubes containing blood samples, in radial disposition.

Furthermore, the top surface of the centrifuge head is polished and engraved or otherwise marked with successive, radially spaced percentage lines from 0 to 100% spiral form; such lines being visible through the tray for visual alignment with the upper and lower ends of the blood sample in a given tube upon suitable rotation of the tray relative to the head, thus providing a direct percentage reading at the division point between the serum and the packed red cells in the tube accruing from centrifuging action.

Thus, as shown in FIG. 1, 10 designates a combination centrifuge and hematocrit reader embodying the invention. The same comprises a motor 11 with a vertical shaft 12 to which a bushing 13 is secured by a set screw, not shown. Bushing 13 includes a radial flange 14 at the lower end thereof which carries upstanding driving pins 14A.

A flat circular head 15 is mounted on bushing 13, said head including a depending hub portion 16 having a central opening 17 to receive the bushing and recesses 17A to receive the driving pins 14A. The head 15 is formed of aluminium or other light metal or alloy and has a polished top surface 18 for the purpose hereinafter appearing.

Head 15 also includes an upstanding annular rim portion 19 and the top surface 18 is slightly recessed relative to an inner annular surface portion 20 and an outer annular surface portion 21 extending to rim portion 19;

'- said annular portions 20, 21 being of limited radial dimenprises an upstanding annular rim portion 23, an annular,

upstanding hub portion 24 of limited radial extent with a central opening 25 for passing bushing 13; and a pair of concentric, annular, upstanding wall portions 26, 26A on top surface 27 thereof. Wall portions 26, 26A are respectively spaced inwardly of and adjacent to rim portion 23 and hub portion 24.

The wall portions 26, 26A are formed with grooves 28, 29 respectively, disposed in radial alignment, for receiving therein capillary tubes CT which contain blood samples to be centrifuged. A soft rubber ring 30 is mounted in an annular groove 31 in tray surface 27 for contact with rim portion 23. When tubes CT are placed in grooves 28, 29; their outer ends are adapted to abut ring 30, while a soft rubber gasket 32 of circular section and located in the annular space between hub portion 24 and wall portion 26A provides means for resiliently and releasably engaging the inner ends of said tubes CT.

Thus the tubes CT may be readily snapped into the grooves 28, 29 and will not he accidentally dislodged from tray 22 as the same may be carried to and from the centri-fuge. Yet the tubes CT may be readily and quickly removed from said grooves due to the .resilient ring 30 and gasket 32.

A circular cover plate 33 'with a central opening 33A is sw-ivelly mounted on the underside of a nut 34 by means of a flanged ring 35 and spacer ring 36, which are secured to nut 34 by screws 37 and form an annular groove to loosely receive therein the inner edge 38 of plate 33 at the opening 33A therein. The nut 34 may thus be screwed down on the upper threaded portion of bushing 13 to thereby press the peripheral portions of cover plate 33 against ring 30 and to enclose tubes CT on tray 22. p

The centrifuge 10 is provided with the usual base and housing for enclosing motor 11, as well as a hinged cover 3 for enclosing the head 15 and tray 22, not shown; and detailed in Patent 2,783,938.

The capillary tubes CT are prepared for receiving blood samples, in a known manner, as by sealing one end thereof with soft plastic 39 or preformed insert plugs. In either case, the seal 39 or plug has a determined length to thus locate the inner end thereof 40 at a point which when the tube is disposed in grooves 28, 29 of tray 22 with the outer end thereof abutting ring 30; will register with the outer edge of wall portion 26 on tray surface 27.

The capillary tubes CT are then filled with blood Samples in the usual manner and disposed in the grooves 28, 29 of tray 22. The centrifuge is then operated to rotate head 15 and associated cover plate 33 with the tubes CT therebetween, for a predetermined time interval, in a manner known in the art. The blood samples in the tubes CT are now stratified to provide a packed red cell portion R and a serum portion S with a visible separation point therebetween as at D.

Means is provided for reading the percentage of packed red cells R in each of the tubes CT, immediately after centrifuging and without removing the tubes from the centifuge. To this end, the polished surface 18 on head 15 is engraved or otherwise marked with radially spaced spiral scale lines 41. Such scale lines 41 are suitably spaced to represent percentages on a scale from at point 40 to 100% with every tenth line suitably numbered as 10, 20, 30, etc.

After the centrifuging operation is completed, nut 34 is unscrewed from bushing 13 to remove cover plate 33, and thus expose tray 22 with the stratified blood samples in tubes CT. Since the volume of the blood sample may vary somewhat from tube to tube; the tray 22 is rotated relative to head 15 to align the top of the blood sample in a particular tube CT, as at T with the appropriate portion of the 100% scale line 41 on surface 18 of the head 15.

While in this position, the separation or demarcation point D in the particular tube CT is visually registered with the underlying scale line 41 and its percentage may be read directly, as for example, 40% as shown in FIG. 2.

The tray 22 may also be used without gasket 32, which permits the tubes CT to be moved radially in their grooves 28, 29 to align point 40 with the 0% scale line on head 15, when point 40 does not happen to coincide with such scale line as previously described, due to nonuniformity in length of seal 39. It is understood that head 15 may also be marked on its surface 18 with successive numerals or other indicia to identify the respective tubes CT disposed in grooves 28, 29.

Cover plate 33 is formed of metal; but also may be formed of transparent plastic. In such case, in lieu of scale markings on the head 15; the markings may be engraved or otherwise formed on cover plate 33', as indicated in FIG. 3. Thus, after centrifuging the tubes CT, the cover plate 33 may be rotated relative to tray 22, to register the 0% and 100% lines with the lower and upper ends of a blood sample in a selected tube CT, as previously described, to provide a direct percentage reading at point D in the stratified blood sample.

Also, the tray 22, together with its tubes CT and cover plate 33, may be removed from the centrifuge device; and mounted on a suitable support spindle, not shown, which permits relative rotation of the plate 33 and tray 22, to provide readings as described above. Thus, the centrifuge is released for use with another tray 22 and associated tubes CT.

A modified form of the tray construction is shown at 22A, in FIGS. 4, and 6. The tray 22A has open bottom portions defined by the rim 23A, the hub 24A and spoke portions 45 which interconnect said rim and hub. The rim 23A includes a depending annular flange portion 46 and hub 24A includes a depending annular flange portion 47; the flange portions 46 47 being of a radial 4 dimension less than that of the rim 23A and hub 24A, respectively.

The centrifuge head 15A is formed on its top surface with annular grooves 48, 49 to receive therein flange portions 46, 47 respectively of tray 22A. The hub 24A is formed with radial grooves 50 and rim 23A is also provided with radial grooves 51, respectively aligned with grooves 50, to receive therein sample tubes CT. As indicated in FIG. 5, the grooves 50, 51 are so disposed as to locate tubes CT in slightly raised relation to the top surface of head 15A, to thereby facilitate visual reading of the scale or percentage markings on the head 15A.

Means may be provided on tray 22A for releasably retaining tubes CT in their grooves 50, 51, as previously described. Also, tray 22A may be with the cover 33, or cover 33', as previously described.

As various changes might be made in the embodiments of the invention herein disclosed without departing from the spirit thereof, it is understood that all matter herein shown or described shall be deemed illustrative and not by way of limitation, except as set forth in the appended claims.

What is claimed is:

1. In a centrifuge having a flat, horizontally disposed rotatable head, a tray removably mounted on said head and rotatable relative thereto, and means for clamping said tray to said head for conjoint rotation, said tray including radially disposed grooved portions on the upper surface thereof for holding capillary tubes carrying blood samples, which samples stratify between the upper and lower ends thereof upon rotation of said head, said tray being transparent and the top surface of said head having radially spaced percentage scale markings thereon including 0% and 100% markings and markings intermediate the 0% and 100% markings visible through said tray whereby said tray may be rotated relative to said head to visually register the upper and lower ends of the blood sample in the tube with said 0% and scale markings on said head and to provide a visual intermediate scale reading registering with the demarcation point of the strata of the blood sample in said tube.

2. In a centrifuge having a head rotatable about a vertical axis, a tray removably mounted on said head for relative rotary movement, means for releasably clamping said tray to said head for conjoint rotation, said tray including radially extending grooved portions on the upper surface thereof for receiving therein capillary tubes carrying blood samples which stratify upon rotation of said head, said tray being transparent and said head having on the top surface thereof an annular zero line marking and a series of successive radially spaced spiral percentage line markings including a 100% line marking, said markings being visible through said tray upon release from said head whereby said tray may be rotated relative to said head to bring the lower and upper ends of said blood sample in registry with the zero and 100% markings respectively, thereby providing a visual percentage reading by registration of the demarcation point of the stratified blood sample With one of said percentage line markings.

3. A hematocrit reader comprising a pair of circular members having opposed faces in adjacent relation and arranged for relative rotation about a common axis, one of said members including a plurality of radially disposed groove means on one face thereof for mounting thereon capillary tubes containing stratified blood samples in a radial disposition, the other member being formed with successive, radially spaced spiral percentage line markings, one of said members having transparent portions whereby said members may be rotated relative to each other to bring the opposite ends of a sample in a selected tube into alignment with a selected pair of percentage line markings respectively, thereby allowing for a visual percentage reading through alignment of a percentage line marking intermediate said pair of line markings with the demarcation of the strata of the blood sample in said tube.

4 A reader as in claim 3 wherein said one member is a transparent tray and the other member is a centrifuge head.

5. A reader as in claim 3 wherein said one member is a tray and the other member is a transparent plate overlying the tubes mounted on said tray.

6. A hematocrit reader as in claim 3, wherein said one circular member comprises a circular tray formed on its upper surface with radial grooves to receive therein capillary tubes containing stratified blood columns, and said other circular member comprises a transparent cover plate for said tray disposed over said tubes and arranged for relative rotation, said cover plate having thereon radially spaced spiral percentage marking lines from zero to 100% whereby relative rotation of said plate and tray to bring the opposite ends of the column in a tube into alignment with Zero and 100% lines will provide a direct visual percentage reading at the alignment of the division point of a column strata with a percentage marking line.

7. A hematocrit reader as in claim 3 wherein said one circular member comprises a circular tray for carrying sample tubes, said tray comprising a rim portion, a hub portion and spoke portions interconnecting said rim and hub portions, said rim and hub portions being formed with radially aligned grooves to receive sample tubes therein.

8. A tray as in claim 7 wherein said rim and hub portions include annular flange portions depending from the underside thereof.

9. A hematocrit reader as in claim 3 wherein said other circular member comprises a rotatable head, and said one circular member comprises a tray removably mounted on said head, said tray comprising annular rim and hub portions and spoke portions interconnecting said rim and hub portions, said rim and hub portions being formed with radially aligned grooves for receiving sample tubes therein, said rim and hub portions including annular flange portions depending from the undersides thereof, said head being formed with annular grooves to receive said annular flange portions therein, the grooves in said rim and hub portions being located to dispose said sample tubes in slightly spaced relation to the top surface of said head.

10. A hematocrit reader comprising a pair of circular members having opposed faces in adjacent relation and arranged for relative rotation about a common axis, one of said members including radially disposed means on one face thereof for mounting thereon a plurality of capillary tubes containing stratified liquid samples, said tubes being in a radial disposition on said one member, the other member being formed on one surface thereof with radially spaced arcuate percentage markings, one of said members being of a transparent character whereby said members may be rotatably related to each other to bring the opposite ends of a sample in a capillary tube into visual alignment with selected percentage markings, thereby allowing for a visual percentage reading through visual alignment of the demarcation of the strata in said capillary tube with a percentage marking.

11. In combination, a centrifuge having a flat circular head member rotatable about a vertical axis, a circular tray carried by said head member, said tray being rotatable about said vertical axis relative to said head member, said tray having radially disposed groove means for mounting thereon capillary tubes carrying stratified blood columns, said head member being formed on the upper surface thereof with radially spaced spiral percentage lines including 0% and lines, said tray and head member being rotatable relative to each other to bring the opposite ends of the blood column in a selected tube on said tray into registry with the 0% and 100% percentage lines respectively, whereby the demarcation point between the strata of the blood column in said selected tube will register with a percentage line intermediate said 0% and 100% percentage lines, said tray being separable from said head member to allow said tubes to be carried in said tray apart from said centrifuge.

12. A reading device comprising a pair of flat circular members in superposed coaxial relation, means for mounting said members for relative rotation about a common axis and for separating one of said members from the other member, said one member including means for mounting a plurality of sample tubes containing stratified material thereon in radial relation to each other, the other member being formed with radially spaced spiral percentage markings including 0% and 100% markings, said members being relatively rotatable to locate a selected sample tube on said one member with the opposite ends of the stratified material therein in registry with the 0% and 100% percentage lines respectively on said other member and to bring the demarcation point between the strata of the Stratified material in said selected tube into registry with a percentage line intermediate said 0% and 100% percentage lines, said one member being independently portable for carrying said sample tubes into and out of reading relation with said other member.

References Cited by the Examiner UNITED STATES PATENTS 446,248 2/91 Cooper 233-26 495,653 4/93 Augustenborg et al. 233-26 X 548,717 10/95 Metzger 233-26 1,648,369 11/27 Svedberg et a1. 233-26 2,179,839 11/39 Brosnan 233-26 X 2,616,619 11/52 MacLeod 233-26 X 2,750,671 6/56 Jones 33-143 2,783,938 3/57 Grela et al 233-26 X 2,831,252 4/58 Weichselbaum 33-143 2,885,145 5/59 Danielsson et a1 233-26 3,009,388 1l/61 Polanyi 233-26 HARRY B. THORNTON, Primary Examiner.

HERBERT L. MARTIN, ROBERT F. BURNETT,

Examiners. 

1. IN A CENTRIFUGE HAVING A FLAT, HORIZONTALLY DISPOSED ROTATABLE HEAD, A TRAY REMOVABLY MOUNTED ON SAID HEAD AND ROTATABLE RELATIVE THERETO, AND MEANS FOR CLAMPING SAID TRAY TO SAID HEAD FOR CONJOINT ROTATION, SAID TRAY INCLUDING RADIALLY DISPOSED GROOVED PORTIONS ON THE UPPER SURFACE THEREOF FOR HOLDING CAPILLARY TUBES CARRYING BLOOD SAMPLES, WHICH SAMPLES STRATIFY BETWEEN THE UPPER AND LOWER ENDS THEREOF UPON ROTATION OF SAID HEAD, SAID TRAY BEING TRANSPARENT AND THE TOP SURFACE OF SAID HEAD HAVING RADIALLY SPACED PERCENTAGE SCALE MARKINGS THEREON INCLUDING 0% AND 100% MARKINGS AND MARKINGS INTERMEDIATE THE 0% AND 100% MARKINGS VISIBLE THROUGH SAID TRAY WHEREBY SAID TRAY MAY BE ROTATED RELATIVE TO SAID HEAD TO VISUALLY REGISTER THE UPPER AND LOWER ENDS OF THE BLOOD SAMPLE IN THE TUBE WITH SAID 0% AND 100% SCALE MARKINGS ON SAID HEAD AND TO PROVIDE A VISUAL INTERMEDIATE SCALE READING REGISTERING WITH THE DEMARCATION POINT OF THE STRATA OF THE BLOOD SAMPLE IN SAID TUBE. 